Numerical Investigation Of Shock Waves/boundary Layer Interaction In Hypersonic Inlet

Hypersonic flight technology is of great significance to national defense security,space exploration and economic development,and its development is inseparable from the achievement of scramjet.As an important part of the scramjet engine,the performance of the inlet is related to whether the entire propulsion system can work stably.In the flow of hypersonic inlets,one of the most common phenomena is shock waves/boundary layer interaction.The existence of this phenomenon makes the flow field structure in the inlet very complicated and may have an adverse effect on the performance of inlet.Therefore,it is necessary to conduct an in-depth study on its flow mechanism.This thesis conducts a numerical simulation of this problem in order to enhance the understanding of this flow phenomenon,the main contents include:(1)A typical shock waves/boundary layer interaction in supersonic compression corner was simulated.The parameters of the boundary layer in front of the corner were made sure to be the same in the calculations.Then four turbulence models were used to calculate the compression corners of different angles.The results were compared with experimental data.And it was found that BSL model and BSL Reynolds stress model had good predication for pressure coefficient,wall friction coefficient and separation zone in shock waves/boundary layer interaction in compression corner.(2)A numerical simulation of typical two-dimensional mixed compression hypersonic inlet was carried out.The difference of results and the reasons were compared.Combined with the conclusion of Chapter 3,it is considered that the BSL Reynolds stress model is more suitable for shock waves/boundary layer interaction problem than the other three models.Then the effects of wall temperature on the flow structure and performance parameters of the inlet are simulated.It was concluded that the increase in wall temperature enhances the shock waves /boundary layer interaction and reduces the performance of the inlet.(3)The shock waves/boundary layer interaction in three-dimensional inlet was studied.The difference in flow structures in the inlet of the three structures,which without sidewall,with a large sidewall and with a small sidewall were compared.The interaction between the boundary layer and the compression shock wave and the influence on the throat separation area are analyzed in detail.Then the inlet performance parameters of different structures are compared.Finally,the flow field structure change and performance of inlet with small sidewall under different angles of attack were calculated.The results show that the angle of attack affects the development of the boundary layer of the inlet and the Mach number in the inlet,which in turn affects the shock waves/boundary layer interaction in the throat.Deviation from the design angle of attack will cause the decline of total pressure coefficient.And the angle of attack is positively correlated with the captured mass flow rate and static pressure ratio of the outlet,and negatively correlated with the flow capture coefficient.